In a surprising reversal Tuesday, golf's two governing bodies scrapped plans to allow recreational players in the United States to use so-called hot drivers, designed to hit the ball farther.

The modified policy means Americans cannot use the thin-faced drivers in club tournaments or to post a score for their handicap index.

The plan that was to take effect Jan. 1 would have allowed average U.S. players to use the hot drivers until 2008. The decision Tuesday does not affect players in the rest of the world, who already were told they can use the drivers until then.

While Tuesday's change was meant to avoid confusion, the new policy by the U.S. Golf Association and the Royal & Ancient Golf Club could lead to chaos in the equipment market, already geared up to sell the new drivers.

A large display window at the New York Golf Center in Manhattan was devoted entirely to an exhibit of Taylor Made's R500 series of thin-faced drivers.

"I just lost a customer because of the ruling," salesman Frank Cole said. "I had been telling people, 'Buy the Taylor Made now. Get used to it. And in January, when you're comfortable with it, it will be legal.' Now I'm going to have guys coming in, bringing their clubs back for a refund. The next week is going to be a nightmare."

The change also brought an angry response from Callaway Golf, the first U.S. company to promote drivers that make the ball spring off the club more quickly.

"We're not going to be able to sell our best technology to golfers that I know will help them enjoy the game," Callaway CEO Ron Drapeau said. "That's sad for the 25 million golfers in the United States under this jurisdiction."

Taylor Made declined comment until it could talk to its retailers.

The R&A makes the rules of golf for everywhere in the world except the United States and Mexico, which fall under the jurisdiction of the USGA.

The two rules makers had different equipment standards for drivers. The USGA set a limit of 0.83 coefficient of restitution (how quickly the ball springs from the clubface), while the R&A did not impose any limits.

That meant players could use the thin-faced drivers at the British Open or World Golf Championships held overseas, but not on the PGA Tour or the three American majors.

A compromise proposed in May would have allowed recreational players to use drivers with a COR of 0.86 for a five-year period, starting next year. Beginning in 2008, the worldwide limit would revert to 0.83.

It did not affect touring pros. The organizations recommended that "highly skilled players" use drivers that did not exceed 0.83.

Why the turnabout?

USGA officials said two months of feedback - customary when they propose rules changes - indicated the compromise was confusing to players and manufacturers. Drivers would be illegal until Jan. 1, legal for five years, then illegal again.

R&A secretary Peter Dawson said several Japanese companies complained about the quick implementation of the new limit (0.86), since they previously had no limits.

"The R&A didn't like the 0.86 (limit), and we didn't like 0.86 in the first place. We only agreed to it as a step toward getting a compromise," USGA executive director David Fay said. "When the R&A said to forget about 0.86, we said there was no need for us to have it."

In the meantime, stores like the New York Golf Center are stuck with the drivers, which sell for $500-$700 each.

"We're real upset," store president Jay Shin said. "A couple of months ago, the USGA said it was going to change the rule, and we sent out 10,000 e-mails to our customers announcing a promotion with Callaway."

He told customers they could use the ERC II and the Taylor Made R500 in club competitions starting in January, and Shin ordered 1,000 drivers from the companies.

"In the last two months, since the USGA's original ruling, we sold 400 to 500 of them," he said. "Now, if a customer comes back and says, 'I don't want to use an illegal driver,' what am I going to do?"

Fay was hardly sympathetic toward companies that already had geared up for the proposed policy change in January.

"They knew it was a proposal and not final," he said. "If they marketed clubs based on the proposal of May 9, then they jumped the gun."

Drapeau said Callaway has sold 300,000 ERC II drivers, more than 100,000 of those in the United States. He said anyone who bought an ERC II through a recent promotion would be allowed to exchange it for any other Callaway driver.

The R&A has said it doesn't believe thin-faced drivers alone are a threat to the game, and Dawson said he only agreed to a limit in 2008 for the sake of compromise.

"We never thought much of COR questions. I don't suppose it matters where the limit falls," he said. "But uniformity is clearly very important. Golf deserves one set of rules."